
B-65232EN/03 FANUC AC SERVO AMPLIFIER β series 8.CAUTIONS FOR SAFETY STANDARDS RELATED TO AMPLIFIER INSTALLATION
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8.2 STANDARD CATEGORIES RELATED TO INSULATION
DESIGN
(1) Insulation between circuits and protective grounding
The amplifiers are designed to the DIN VDE 0160 standard, so
they conform to Part 1 of DIN VDE 0110 and related standards.
- The primary side (power source and main circuit side) is
separated from the secondary side (control circuit side) for
safety with reinforced insulation.
- The circuits are isolated from the protective grounding with
fundamental insulation.
The power supply main circuit and heat sinks are isolated from
one another with fundamental insulation. So, the grounding
terminal of a heat sink should be connected to the protective
grounding line as shown in Section 8.7.
(2) Installation category (overvoltage category)
DIN VDE 0110 (electric device insulation harmony) classifies
power supply equipment by the amplitude of an impulse voltage
contained in the power supply for the amplifier in reference to a
ground potential. The β series servo amplifiers are classified in
installation category (overvoltage category) II.
This category requires that the rated impulse dielectric strength
(measured in reference to a ground potential) in a power supply
connected to the amplifiers be not higher than 2.5 kV. Any
impulse voltage higher than 2.5 kV in reference to a ground
potential must be eliminated from the power supply.
Generally, an isolation transformer at the input section of the
power supply of a machine would make the machine satisfy that
requirement. If the power supply does not use an isolation
transformer, a lightning surge absorber should be installed
between the power and ground lines to suppress an impulse
voltage higher than 2.5 kV in reference to a ground potential.
(3) Installation environment contamination level and power
magnetics cabinet protection grade
EN60204-1 (Chapter 13/Section 13.3) states that machines to be
installed in an ordinary factory environment satisfy protection
grade IP54 or higher against dust debris, cutting fluid, and
cutting chips. The β series servo amplifiers do not satisfy IP54
unless an additional measure is taken. So they should be
installed within a power magnetics cabinet that satisfies IP54.
The IP grade to be satisfied varies with the environment
(atmosphere) in which the machine is installed. So, it is
necessary to select the protection grade for the power magnetics
cabinet according to the environment in which it is installed.
The β series amplifiers are designed on the assumption that they
are installed in an environment with a contamination level of 2.
So, the contamination level for the power magnetics cabinet
must be 2 or below.